G01

Invoice Identification

Opens an 880 — invoice date/number and, if referenced, the PO it bills.

Key elements

Element	Name	What it carries
G0101	Date	Invoice issue date.
G0102	Invoice Number	Your invoice number.
G0104	Purchase Order Number	PO this invoice bills — used to auto-match, the same role as the 810's BIG04.
G0105	Vendor Order Number	The vendor's own reference to the buyer's PO, if different.

Key elements only — the ones that matter in retail trade, not the full element list.

See a real G01 in context — paste any X12 and the Inspector breaks out every segment.